With the spread of portable terminals in recent years, development of mobile base station devices which can easily be installed as access points for portable terminals has been conducted. As such technology, for example, the wireless telephone system described in Patent Document 1 is an example. In this wireless telephone system of the prior art, by managing access to a home base station based on identification information of portable terminals, communication fees are calculated for each of the connected portable terminals.    Patent Document 1: Japanese Patent Laid-open No. H6-311099